Hi

I've been noticing that when I record real bass parts through my Firebox into Garageband on my G5, despite sounding fine monitored through my headphones, when I play it back there's a weird and unpleasant effect that sounds vaguely like there are two basses playing, and slightly out of tune with each other. Basically totally crappy sound. It seems to happen even when I try different effects (e.g. modern rock bass, edgy bass, etc). So I just tried playing my bass through input 1 on the firebox and it sounds much better. I also tried singing through input #2 and although nothing as bad as with the bass, the sound seems somewhat weaker (?). Any ideas what the problem might be?

Thanks

Ken

Hi again

So I think the problem is the result of changing the tempo of the track. Why does changing the tempo mess up the sound so bad and is there anything I can do to fix it? Besides playing my stuff in real time?

Thanks again...

I am not sure how you are monitoring the audio. but make sure that you are not hearing the playback from two different monitoring sources. I monitor mainly through my mixer board, but if for some reason, I have my software also monitored during the playback via the Q mix, I will at times get a very weird effect on my recorded tracks. Just a thought!!! I will keep my thinking cap-on and let you know if I ponder any other possible reasons this could be happening. As the post states below, make sure that the song tempo and kHz recorded are all congruent. If this is off, major problems will surface. Good luck!

Allen

i've never tried recording into Garageband & I don't know how it treats audio - I have had ok results recording bass so far using Ableton Live & a Mackie Onyx mixer i have been getting around that weird "flange/chorus" thing by using warp markers (adding them where neccessary) when doing tempo changes in Ableton as well as doing some "time stretching" techniques in Acid Pro that reduced those weird artifacts by forcing more or less divisions - Does GB have some time stretching algorythms? Look into those- you may not completely eliminate the artifacts but you may get a more listenable result-

Make sure that your firebox is set to 16 bit 44.1kHz. Unless you are using GB2..

Funny you should mention that.

When I first installed my Firebox, I was perturbed to find that my Firebox Control window doesn't have dialog boxes for Sample Rate, Latency or Clock Source. The words "Hardware Settings" are there but not the aforementioned settings - "Input Level Boost" is directly beneath. Since then I've pretty much ignored that fact but now I guess it needs to be addressed. Unfortunately I don't know how.

Thanks, Ken

Me again - terribly sorry... this thread probably be called "changing tempo without loss of sound quality."

Having done a wee bit of research on this issue, here's what I've come up with.

GB uses a technique called "granulation" to alter tempos, as opposed to the "beat slicing" technique developed by Propellerhead used by Reason and others. This technique "warps" the segment rather than "slicing" it into very brief segments. With slicing, tempo can be manipulated without as much sound distortion as results from granulation. However, apparently even slicing is limited in its application, as it works best with short loops and "gappy" (as opposed to continuous) instruments such as drums.

One major example of software used to slice loops is Propellerhead's "Recycle" which creates a REX 2 file (a file which contains your sliced-up loop). Reason, Cubase and Logic all support REX 2 loops. However, it seems that the process of slicing is somewhat laborious and possibly not suitable for changing the tempo of a track that doesn't repeat every 4 measures.

This info is a summary of this Sound on Sound article:
http://www.soundonsound.com/sos/jun04/arti...beatslicing.htm

Having not tried this, I'd be interested to hear what others have to say about this issue. My problem is that I can't play bass or guitar very well and would like to be able to play parts at a lower speed and then speed them up digitally in a way that doesn't sound like ass.

Ken

You've probably already realised that recording a live instrument at the correct tempo is the simplest way to avoid any kind of artifacts. Or, indeed, sounding like ass. But it really is.

GarageBand doesn't have Strip Silence (or something similar), unfortunately. This works very nicely in Logic Pro and now BIAS' Peak Pro 5 to chop up a recorded part so you can move any notes you bodged during recording.

Trouble is, any kind of time-stretchy thing (like Apple Loops in GB) is always going to give you less than perfect results - it comes with the territory. Tools like Melodyne and Live have specialised in perfecting the algorithms to allow us to warp audio at will and still can't always guarantee 100% artifact-free results.

I'm not being a smart-arse, but practice really does make perfect. If you can play the part - even a few bars at a time and then compile the best bits into one perfect whole - you'll be much happier with the finished recording.